eljefe62

Is the 3rd gen LSD compatible to be swapped into 2nd gen?
i have an s5 na
i read something about it on rotary perf.'s website, but wasn't too specific

Phu5ion

i don't know if the 3rd gen lsd will swap right in, but another option is to find a GTU rear end and that will bolt right up. there are plenty of guys on here that have talked about doing that swap and might be easier.

i suppose you are asking in the first place because you already have a 3rd gen LSD available and haven't looked for a GTU parts car.

FCdemon

if you mean GTU, you must be talking about the '88 GTU or the '89-91 GTUs model.

eljefe62

If GTU is base model, i have that anyways
i just thought the 3rd gens were "technologically advanced" as opposed to fc's
and generally would provide better grip

Hot_Dog

The 3rd gen uses a torsen LSD with a short drive pinion gear. Also, the 3rd gen differential case is different from the 2nd gen case. Specifically, the 3rd gen differential case bolts to a PPF whereas the 2nd gen case has arms that bolt to the underbody. The 3rd gen torsen gear case is interchangeable with the 2nd gen gear case. You will need to pull out your existing gear case and swap the ring gear to the torsen, and then readjust the backlash. You may want to first talk to Mazdatrix about this swap to see if they have any suggestions.

Hot_Dog
90 RX7 GXL
02 RSX-S

Hot_Dog

Also, forgot to mention this, but my biggest concern would be the output flanges and drive shafts. Not sure if the NA or TII output flanges would fit into the torsen side gears. You need to be concerned about the number of splines and length. Alternatively, the 3rd gen drives would certainly fit wrt the splines, but you need to check the length. Also, I don't know if the 3rd gen drive shafts with fit into the 2nd gen hubs. Lot of uncertainities here. Like I said earlier, it's probably best to discuss this swap with Mazdatrix before attempting. It might save you a lot of unforeseen grief.

Hot_Dog
90 RX7 GXL
02 RSX-S

eljefe62

Alright thanks
would the swap be worth it?
mainly for daily driver, but weekend racing also

GLHS

is it worth it to you to do this swap?

Your the one doing the swap and know the cost to swap it out. Is it worth it... Probadly not, unless you have got massive amounts of power. Its not worth it for a 160 hp engine..

Phu5ion

I'd like to quote rico05 on this from an old thread on LSD's.

https://www.rx7club.com/forum/showth...hlight=GTU+LSD

eljefe62

Thanks for all the info, I guess I will give mazdatrix a try, to find out what could be done
by the time I'm ready for this swap, I'd probably be around 185-190 HP

Rxmfn7

iTrader: (4)

Truthfully, for 190HP, it is in no way worth all the trouble. Yes youd probably want a LSD, just for traction purposes when trying to launch, but a regular LSD from and FC would be perfectly good enough. A S5 LSD would probably be best, since they dont wear out as some S4 LSDs are known to (although mine seems to work fine).